When coaching a sports team or a student, it is often desirable, or necessary, for a coach to communicate instructions effectively and clearly to the sports team or student.
In some sporting activities, such as team sports that are played on an open field, unassisted verbal communication is sufficient.
In other situations, however, external factors may preclude the use of unassisted verbal communication. For example, in sports such as water skiing, surfing, sailing, or sky diving, several factors such as external noise, and/or the proximity of the coach to the student may preclude the use and effectiveness of unassisted verbal communication. In such cases, the coach may rely on visual signals to communicate with the student. Such visual signals also have shortcomings. For example, the student may misinterpret the visual signal, or may not immediately see the visual signal.
Such limitations restrict the effectiveness of the coaching, and limit the development of the student. Furthermore, in coaching situations where the instructor cannot effectively and immediately communicate with the student, the student may be placed at a higher risk of injury or misadventure.
Such considerations are also paramount in rescue operations and in many military situations. There is generally a need in many situations to communicate instructions quickly and clearly to minimise the probability of injury to the individual or maximise the effectiveness of the instructions given by the coach.